As a video signal processing speed increases, methods for encoding/decoding ultra high definition (UHD) video signals are studied. UHD video is defined as a high definition (HD) video image having a resolution corresponding to quadruple or 16 times the resolution of HD video. High efficiency codec technology for transmitting UHD video television signals using a single codec is developed by some standardization organizations. However, current broadcast systems cannot transmit/receive UHD video even if a method for encoding/decoding the UHD video is provided since a method for transmitting the UHD video is not defined in the current broadcast systems. Further, even when a system for transmitting/receiving the UHD video is provided, the system is less likely to be utilized unless the system is compatible with conventional video transmitting/receiving systems. Accordingly, compatibility with conventional broadcast or video transmitting/receiving systems becomes an issue.
For example, when a conventional HDTV receiver receives UHD video, there is no method for receiving or displaying HD video without any problems. Particularly, both UHDTV and HDTV need to receive or output video signals without any problems using one UHD video in a process of transmitting UHD signals. However, a method for receiving or outputting video signals using one UHD has not been provided. Especially, a method for extracting 60 interlaced video frames from 60 progressive video frames has not been proposed.
That is, there is no method for viewing HD compatible images without any problems when an HDTV receiver having a different scan mode and a different frame rate receives UHDTV streams.